README: Update parse output to match Postgres 16

Author: lfittl

Diff for: README.md

@@ -59,7 +59,7 @@ func main() {
 Running will output the query's parse tree as JSON:
 
 ```json
-{"version":150001,"stmts":[{"stmt":{"SelectStmt":{"targetList":[{"ResTarget":{"val":{"A_Const":{"ival":{"ival":1},"location":7}},"location":7}}],"limitOption":"LIMIT_OPTION_DEFAULT","op":"SETOP_NONE"}}}]}
+{"version":160001,"stmts":[{"stmt":{"SelectStmt":{"targetList":[{"ResTarget":{"val":{"A_Const":{"ival":{"ival":1},"location":7}},"location":7}}],"limitOption":"LIMIT_OPTION_DEFAULT","op":"SETOP_NONE"}}}]}
 ```
 
 ### Parsing a query into Go structs